21213600655551 has 8 divisors (see below), whose sum is σ = 28286669521584. Its totient is φ = 14141466113280.

The previous prime is 21213600655531. The next prime is 21213600655631. The reversal of 21213600655551 is 15555600631212.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21213600655551 - 2⁶ = 21213600655487 is a prime.

It is a super-2 number, since 2×21213600655551² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21213600655531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 233527960 + ... + 233618781.

It is an arithmetic number, because the mean of its divisors is an integer number (3535833690198).

Almost surely, 2^{21213600655551} is an apocalyptic number.

21213600655551 is a deficient number, since it is larger than the sum of its proper divisors (7073068866033).

21213600655551 is a wasteful number, since it uses less digits than its factorization.

21213600655551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 467161881.

The product of its (nonzero) digits is 270000, while the sum is 42.

The spelling of 21213600655551 in words is "twenty-one trillion, two hundred thirteen billion, six hundred million, six hundred fifty-five thousand, five hundred fifty-one".